40 CFR 50.6 - National primary and secondary ambient air quality standards for PM 10 .

§ 50.6 National primary and secondary ambient air quality standards for PM10.
(a) The level of the national primary and secondary 24-hour ambient air quality standards for particulate matter is 150 micrograms per cubic meter (µg/m3), 24-hour average concentration. The standards are attained when the expected number of days per calendar year with a 24-hour average concentration above 150 µg/m3, as determined in accordance with appendix K to this part, is equal to or less than one.
(b) [Reserved]
(c) For the purpose of determining attainment of the primary and secondary standards, particulate matter shall be measured in the ambient air as PM10 (particles with an aerodynamic diameter less than or equal to a nominal 10 micrometers) by:
(1) A reference method based on appendix J and designated in accordance with part 53 of this chapter, or
(2) An equivalent method designated in accordance with part 53 of this chapter.
[52 FR 24663, July 1, 1987, as amended at 62 FR 38711, July 18, 1997; 65 FR 80779, Dec. 22, 2000; 71 FR 61224, Oct. 17, 2006]

Title 40 published on 2014-07-01

no entries appear in the Federal Register after this date.

This is a list of United States Code sections, Statutes at Large, Public Laws, and Presidential Documents, which provide rulemaking authority for this CFR Part.

This list is taken from the Parallel Table of Authorities and Rules provided by GPO [Government Printing Office].

It is not guaranteed to be accurate or up-to-date, though we do refresh the database weekly. More limitations on accuracy are described at the GPO site.

United States Code

Title 40 published on 2014-07-01

The following are ALL rules, proposed rules, and notices (chronologically) published in the Federal Register relating to 40 CFR 50 after this date.

  • 2015-01-05; vol. 80 # 2 - Monday, January 5, 2015
    1. 80 FR 278 - National Ambient Air Quality Standards for Lead
      GPO FDSys XML | Text
      Proposed rule.
      Comments must be received on or before April 6, 2015. Public Hearings: If, by January 26, 2015, the EPA receives a request from a member of the public to speak at a public hearing concerning the proposed decision, we will hold a public hearing, with information about the hearing provided in a subsequent notice in the Federal Register .
      40 CFR Part 50